Bacterial canker is caused by Xanthomonas campestris pv. viticola (Xcv). In order to eliminate Xcv from 'Red Globe' plants it was studied: optimal size of meristem tips and axillary buds for cultivation in modified Galzy's medium (MGM); effects of thermotherapy (38ºC/30 days); and action of antibiotics in the elimination of Xcv in infected grapevines. The percentages of contamination by Xcv and regeneration were analyzed and plants obtained were indexed using the semi-selective culture medium nutrient agar-dextrose-yeast extract-ampicilin (NYDAM) followed by a pathogenicity test. The cultivation of 3 mm explants permitted to obtain plants free of bacteria with regeneration 14.3 times higher than 1 mm explants. The thermotherapy of infected plants associated to the in vitro culture did not eliminate the pathogen. The cultivation of 10 mm explants during 40 days in MGM + cefotaxime (300 mg L-1) eliminated Xcv from grapevine plants. The indexation of micropropagated grapevine plants for Xcv infection by using NYDAM medium followed by a pathogenicity test is an economical and efficient alternative to produce plants of high sanity quality.
Vitis vinifera; in vitro culture; phytobacteriology; Xanthomonas campestris pv; viticola